The present invention relates to an improvement in a filter adapted to be connected to a suction hole of an intank pump provided in a tank for storing a liquid, so as to prevent suction of a foreign matter in the liquid.
In such a filter for use with the intank pump, the filter must be kept in abutment against a bottom inner surface of the tank, so as to minimize a residual amount of the liquid not to be sucked into the pump. To meet the requirement, there is disclosed in Japanese Utility Model Laid-open Publication No. 62-203977, for example, a structure such that an elastic member is provided in the filter to press a mesh bag of the filter against the bottom inner surface of the tank.
However, as the elastic member in this structure is formed from a torsion spring, a surface area of the mesh bag to be pressed by the torsion spring is small, and a pressure per unit area applied to the mesh bag by the torsion spring becomes large. In this circumstance, when the pump and the tank are vibrated as in the case that they are mounted on an automobile or the like, the mesh bag is locally worn by the torsion spring due to a large pressure. In the worst case, there is a possibility of breakage of the mesh bag.
The above problem may be cleared by reducing a spring force of the torsion spring. However, since the torsion spring requires to have a spring force enough to stably maintain the abutment of the mesh bag against the bottom inner surface of the tank even if a mounting level of the pump in the tank is somewhat varied, the spring force of the torsion spring cannot be so small. Thus, the local wearing of the mesh bag due to the pressure applied thereto by the torsion spring cannot be avoided.